Quote: Plot - Episode 16 Series 2 - Safe (House)
The episode starts out with teenager Melinda's boyfriend, Dan (Jake McDorman), visiting her at her house. Her mother, Mrs. Bardach, tells Dan to make sure he has washed his hands, up to the elbows. When Dan meets Melinda (Michelle Trachtenberg) and kisses her, she goes into anaphylaxis even though it was a clean room (though she had urticaria on her left forearm beforehand). Mrs. Bardach saves her via the use of an EpiPen, blames Dan, and takes her to the hospital. At the hospital it is revealed that Melinda has a transplant heart operation after her chest was crushed in a car accident. Thus, with a now poor immune system she has to be kept in a constantly clean environment.
Suspicions arise regarding whether Dan has been sneaking into her house. House and his team discover that Dan has been taking penicillin which Melinda is allergic to. Melinda starts having heart problems, followed by paralysis (steppage gait) and none of the treatments seem to be working.
House believes that all these symptoms have been caused by a tick or other bug, currently injecting trace amounts of venom into her bloodstream. During an elevator ride House stops the elevator and proceeds to look for the tick. He finds it in her vagina and removes it. Finally, Melinda's health returns.
Side stories include House playing the hand in warm water trick on Wilson, making him urinate on House's sofa and Wilson filing at House's cane so that House breaks his cane and trips when walking. | 
